Faster compilation speed [zone allocation]

[Robert Dewar]

<        Because the problem is not the garbage collection, its the
allocation pattern.  The proposal to use reference counting allows GCC to
switch to an allocator with better locality -- it's a requirement for the
underlying improvement, not a fix unto itself.
>

But removing garbage collection entirely certainly gives some information.
Another way of examining is to compile on a machine with a large level 2
cache, and watch the compilation time vs size of thing being compiled.